We start our Saturday with wafts of fog. A heavy fog warning is in effect for parts of northern Minnesota and Douglas County in Wisconsin through 10 a.m. Saturday:
Heavy fog warning (grey) until Saturday 10 a.m
National Weather Service
chances of thunderstorms
Isolated showers and thunderstorms will linger over parts of Minnesota and western Wisconsin Saturday morning. We then expect a break in action for most areas, with isolated thunderstorms returning later on Saturday afternoon and Saturday evening.
In the late afternoon and evening isolated strong to violent thunderstorms are possible. The NWS Storm Prediction Center is showing a low risk of severe weather (shaded yellow) across much of central Minnesota and a portion of northern Minnesota today and tonight:

Severe weather forecast Saturday/Saturday evening
NWS Storm Prediction Center/Twin Cities NWS
Low risk means isolated violent thunderstorms are possible. Isolated severe thunderstorms are possible later this afternoon or tonight in the darker green shaded areas, including the Twin Cities.
You can track showers and thunderstorms on the new interactive radar on MPR News’ weather page. You can pan and zoom the radar display on our website to see rain at your location, across Minnesota, western Wisconsin and beyond.
We have updated weather information for Minnesota and western Wisconsin on the Minnesota Public Radio News Network and the MPR News live weather blog.
Saturday temperatures and dew points
Our average high temperature in Twin Cities on September 17th is 73 degrees. Parts of the metro area and southern Minnesota could top 80 degrees this Saturday. Saturday afternoon highs will be in the 70s in central Minnesota and parts of northern Minnesota, with some 60s in the far north:

Highs forecast for Saturday
National Weather Service
Saturday dew points are in the muggy 60s across much of Minnesota and western Wisconsin:

Dew points predicted Saturday 1pm
National Weather Service
To update
A new updraft will be released around 10:20am and will include an outlook for Sunday and the week ahead.
programming note
You can hear my live weather updates Saturday and Sunday at 7:35am, 9:35am and 4:39pm on MPR News.